Advanced Materials Research Vols. 295-297

Abstract: The electrical and dielectric properties of Ba0.3Sr0.7TiO₃ (BST), as a function of annealed temperature and oxygen partial pressure (P(O₂)) , were studied in this paper. The resistivity data were fit to a p type model involving only doubly ionized oxygen vacancies, holes, and accidental acceptor impurities, and it decreased as P(O₂) and temperature increased. The breakdown strength exhibited the same trend with resistivity. The breakdown strength exhibited the same trend with resistivity. The maximum dielectric constant of BST was observed under the lowest P(O₂) at the temperature of 900°C. BST annealed under P(O₂) of 0.1 atm at the temperature of 800°C obtained the highest volume energy storage density.

Abstract: In this paper, it is proposed a new method of free-from surface’s reverse engineering, making data acquisition and surface reconstruction form closed loop system, solving no feedback problems in the measuring and modeling process, shortening the time of the whole reverse engineering, improving the quality of reconstructed models. The core of this paper is used the CMM adaptive measuring method and non-uniform b-spline surface reconstruction method, integrating the free-from surface measuring and modeling in a closed loop system, realizing the CMM real-time online measurement and reconstructed surface real-time update.

Abstract: A novel photochromic diarylethene based on isoxazole moiety was synthesized and its photochromic and fluorescent properties were also investigated. This compound exhibited reversible photochromism, changing from colorless to red after irradiation with UV light both in solution and in poly-methyl methacrylate (PMMA) amorphous film. Also, it exhibited remarkable fluorescence switching in the solid state. The results showed that the diarylethene exhibited a relatively strong fluorescence switch along with the photochromism from open-ring isomer to closed-ring isomer. Using this dithienylethene 1c as optical storage was performed successfully.

Abstract: P-ferrocene-SA/acetylferrocene-CS Bipolar Membrane (BPM) was prepared with phosphorylated agent as the cation exchange layer, and chitosan (CS) modified with acetylferrocene as the anion exchange layer. Zinc/Nickel alloy layer was placed on the surface of cation exchange layer to realize zero polar distance in the cathode chamber. The 2, 3, 5, 6-tetrachlopyridine (2,3,5,6-TCP) was electro-synthesized by reducing of pentachloropyridine(PCP). At the current density of 30mA·cm^-2, the current efficiency was 70.1% and the yield of 2, 3, 5, 6-TCP was up to 96%. Compared with the traditional method, the electro-generation technology greatly eliminated the environmental pollution.

Abstract: The ultimate bearing capacity test is carried on CFST arch bridge model with CFRP slings, and the deflection of tie-beams, CFST arch, crossbeams, decks is also tested. Studies have shown that before the sliping of 4# CFRP sling, the deflection growth of east and west tie-beam, east and west arch both has good symmetry. The deflection growth of crossbeams and decks also has good symmetry, but after the sliping of 4# CFRP sling(located at the middle of west tie-beam), the structural internal forces redistribution appeared. The deflection of west tie-beam increased suddenly, and the mid-span deflection of west tie-beam is larger than that of east tie-beam by 14.6%. The mid-span deflection of east arch is larger than that of west arch by 9.9%. The deflection of crossbeam at 3L/8 and L/4 sections are respectively larger than those of crossbeam at 5L/8 and 3L/4 sections by 13.8% and 5.3%, The deflection of 3#, 2# and 1# decks are respectively larger than those of 4#, 5# and 6# decks by 7.8%, 13.2% and 17.1%. After the snapping of 10# CFRP sling(located at 3L/8 section of east tie-beam), the structural internal forces would appear redistribution. The deflection of east tie-beam would increase suddenly. The mid-span deflection of east tie-beam is larger than that of west tie-beam by 31.7%, and the mid-span deflection of east arch is larger than that of west arch by 21.3%. The deflection of crossbeam at 3L/8 and L/4 sections are respectively larger than those of 5L/8 and 3L/4 sections by 24.7% and 22.5%. The deflection of 3#, 2# and 1# decks are respectively larger than those of 4#, 5# and 6# decks by 16.2%, 24.5% and 28.6%.

Abstract: Aiming at the facing problems of the actual continuous caster in a certain steel mill, a solidification-process heat transfer model about continuously cast bloom of special steel was first established, then the influence of superheat on macrosegregation formation was studied. It is shown that the crater length will become longer, the shell thickness will become thinner with increasing the superheat. Meanwhile, when decreasing the superheat , the value of will decrease and the value of H will obviously increase, then the equiaxed crystal ratio will be raised greatly. However, the bloom centre solidification time will increase. Consequently, attention should be paid to this point when decreasing the superheat in order to lessen the extent of macrosegregation.

Abstract: The air-water interfacial zirconia film composed of nanodisks with self-assembly structure is prepared. Scanning electron microscopy (SEM), Energy Dispersive Spectrum (EDS), X-ray diffraction (XRD) and Transmission electron microscopy (TEM) are used to characterize the film. Furthermore, the heat-treatment of this film is studied by thermogravimetry and differential thermal analysis (TG-DTA), XRD, and Raman spectroscopy (Raman). The results suggest that the zirconia of the samples changes from amorphous phase to t-ZrO₂ phase then m-ZrO₂ phase with the rise of calcined temperature.

Abstract: The brownmillerite structural Ca₂Fe₂O₅ is successfully prepared by high energy milling starting from CaCO₃ and Fe₂O₃. The composition and transformation of phase and structure with different milling time and annealed at 800 °C for 24 h were characterized by the X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) analysis. The results indicate that the high pure brownmillerite structural Ca₂Fe₂O₅ could be efficiently synthesized at lower temperature by the mechanically activated mixtures.

Abstract: In-situ ZrB₂/AZ91 magnesium matrix composite was successfully synthesized with Al/K₂ZrF₆+NH₄BF₄ by Direct Melt Reaction (DMR). The microstructures of the ZrB₂/AZ91 magnesium matrix composite fabricated by direct melt mixing method were investigated. The results show that the size of ZrB₂ particles is less than 1μm and even reaches to 100nm and the shape, amount and size of the β-Mg₁₇Al₁₂ phase in magnesium matrix composite have been greatly changed due to ZrB₂ heterogeneous nuclei.

Abstract: To discover the water structure in glass, two silicate glasses were synthesized under different melting atmospheric conditions. Fourier transform infrared spectrometric analyzer was used to study the OH contents and the infrared spectra bands in 1300-4000cm^-1 of the glasses. The research shows that water contents of glass samples melted under air atmosphere and oxyfuel firing atmosphere are 0.0323wt% and 0.0512wt% respectively. The infrared absorptions in 1300-4000cm^-1 band are dominantly related with water dissolved in glass melt. Water existing in glass is mainly in the form of Si-OH, in addition with some free OH connected with metal cations. The IR absorption of ferrous ion in glass is near 3430cm^-1, while the IR absorption near 2500 cm^-1 does not belong to the vibration of KOH.